Environmentally friendly analysis of sulphonamides in Brazilian honey through automated and miniaturised sample preparation coupled with LC-MS/MS

Increased use of environmentally friendly practices has become a trend in science because of the current awareness regarding climate change and related issues. Similarly for analytical chemistry, considering the development of greener methods for reducing the use of reagents and samples and also toxic waste generation. To meet such goals, automation, and miniaturisation of sample preparation—a well-recognised laborious and time-consuming analytical step—are two promising strategies. This work associates the greener aspects of miniaturisation and the performance of automated sample preparation. Therefore, we proposed an analytical method using a miniaturised extraction column for pre-concentrating sulphamerazine, sulphamethazine, sulphamethoxazole, sulphadimethoxine, sulphathiazole, and sulphachlorpyridazine from honey and cleaning-up the samples. Several variables were optimised: extractive phase, loading flow, loading phase, and loading time. Under optimised conditions, the method showed adequate linearity between 5.0 and 60 ng g⁻¹ with <i>R</i> &gt; 0.99, and also good selectivity and recovery (114.6–124.1%) which are acceptable according to Brazilian legislation. Intra and inter-day precision were in the range 3.0–5.0%. Although sulphonamides were detected in one of the eight commercial honey samples, the value was below the established MRL. The method showed efficiency, while also exhibiting greener characteristics resulting from miniaturisation and automation, representing a promising environmentally friendly alternative for conventional sample preparation methods.

鉴于当前公众对气候变化及相关问题的认知提升，环保型研究范式已成为科学界的主流趋势。在分析化学领域亦是如此，学界正致力于开发更环保的分析方法，以减少试剂、样品用量并降低有毒废物的产生。为达成此类目标，样品前处理——这一公认的费力且耗时的分析环节——的自动化与微型化，成为两种极具前景的解决方案。本研究兼顾微型化的环保特性与自动化样品前处理的性能表现，提出一种分析方法：采用微型化萃取柱（miniaturised extraction column）从蜂蜜中预富集磺胺甲嘧啶（sulphamerazine）、磺胺二甲嘧啶（sulphamethazine）、磺胺甲恶唑（sulphamethoxazole）、磺胺二甲氧嘧啶（sulphadimethoxine）、磺胺噻唑（sulphathiazole）及磺胺氯吡嗪（sulphachlorpyridazine），并完成样品净化。研究对萃取相、上样流速、上样溶剂及上样时间四项变量进行了优化。在优化后的条件下，该方法在5.0~60 ng g⁻¹范围内呈现良好线性关系，相关系数<i>R</i> > 0.99；同时具备优异的选择性与回收率（114.6%~124.1%），符合巴西相关法规的要求。日内与日间精密度均处于3.0%~5.0%区间。尽管在8份市售蜂蜜样品中的1份里检测到了磺胺类物质，但其含量低于规定的最大残留限量（Maximum Residue Limit, MRL）。该方法兼具高效性与微型化、自动化带来的环保特性，可为传统样品前处理方法提供一种极具前景的环保替代方案。